CD8A and neoplasm: Indeed, it is reported that disfunction of FAS‐mediated apoptosis pathway contributing to failure of immunotherapy in CRC.[31] Based on our evidences that PIR expression is negatively correlated with FAS‐initiated cell death, we believe that PIR‐caused silence of endogenous FAS expression in tumor cells may weaken the function of active CD8+ killer T cells in tumor microenvironment and be the potential reason leading to tumor resistance to immune checkpoint inhibitors.